1. Field of the Invention
The present invention relates in general to an antenna provided to a rear window glass of an automotive vehicle and, particularly to the kind suited for transmitting and receiving ultrashort waves allocated to mobile phones and radios for personal or business use installed on an automobile. The antenna is also suited for receiving TV (television) broadcast waves in UHF bands.
2. Background of the Invention
In current automobiles it is customary to use a pole antenna for the transmission and reception of ultrashort waves assigned to mobile phones and radios for personal or business use in Japan. However, the protrusions of a pole antenna from a car body is unfavorable for safety and also for good appearance of the car. Besides, pole antennas are obstructive to car washing and sometimes break.
There have been some proposals of providing an antenna for transmission and reception of ultrashort waves on an automobile window glass. See, for example, JP-A 62-69704 and JP-A (Utility Model) 62-26912. However, window glass antennas proposed until now are considerably low in transmission and reception gains when compared with conventional pole antennas and hence cannot be put into practical use for car telephones or radios for personal or business use.